Fabrication of a micromechanical part purely from synthetic diamond or DLC (diamond like carbon) is very expensive and is not tribologically advantageous due to the unfavourable roughness generated by the thick layer deposition process or by a solid etching method. Consequently, it is currently preferred to coat the micromechanical part using a thin layer of synthetic diamond or DLC, although this does enable obtain all shapes to be obtained, particularly if one portion of the part has to be pierced with a hole.